1. Field of the Invention
The present invention relates to a current sensor measuring the magnitude of an electrical current. In particular, the present invention relates to a current sensor where the reduction of measurement accuracy, caused by an induction magnetic field due to an adjacent current, is suppressed.
2. Description of the Related Art
In a field such as a technology for driving motors in electric vehicles, hybrid cars, and the like, a relatively large current is handled. Therefore, for such use, a current sensor has been desired that is capable of measuring a large current in a non-contact manner. In addition, as such a current sensor, a type of current sensor has been put into practical use, the type of current sensor detecting the change of a magnetic field occurring from a current to be measured, using a magnetic sensor. Since, in a current sensor utilizing a magnetic sensor, the reduction of measurement accuracy due to the influence of a disturbance magnetic field becomes an issue, a method has been proposed that suppresses this.
As the method suppressing the reduction of measurement accuracy due to the influence of the disturbance magnetic field, for example, a method has been proposed that cancels out the influence of the disturbance magnetic field by providing a magneto impedance (MI) element in a direction opposite to a magnetic field occurring from a current to be detected. Such a technique has been disclosed in Japanese Unexamined Patent Application Publication No. 2001-305163.